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Tuesday, 6 December 2016

Scott Adams, the creator of Dilbert, wrote today about how difficult it is for a non-expert to judge science and especially climate science. He argues that for a non-expert it is normally a good idea to follow the majority of scientists. I agree. Even as a scientist I do this for topics where I am not an expert and do not have to time to go into detail. You cannot live without placing trust and you should place your trust wisely.

While it is clear to Adams that a majority of scientists agree on the basics of climate change, Scott Adams worries that they could all be wrong. He lists the 6 signals that this could be the case below and sees them in climate science. If you get your framing from the mitigation sceptical movement and only read the replies to their nonsense you may easily get his impression. So I thought it would be good to reply. It would be better to first understand the scientific basis well before venturing into the wild.

The terms Global warming and climate change are both used for decades

Scott Adams assertion: It seems to me that a majority of experts could be wrong whenever you have a pattern that looks like this:

1. A theory has been “adjusted” in the past to maintain the conclusion even though the data has changed. For example, “Global warming” evolved to “climate change” because the models didn’t show universal warming.

This is a meme spread by the mitigation sceptics that is not based on reality. From the beginning both terms were used. One hint is name of the Intergovernmental Panel on Climate Change, a global group of scientists who synthesise the state of climate research created in 1988.

The irony of this strange meme is that it were the PR guru's of the US Republicans who told their politicians to use the term "climate change" rather than "global warming", because "global warming" was more scary. The video below shows the historical use of both terms.

Global warming was called global warming because the global average temperature is increasing, especially in the beginning there were still many regions were warming was not yet observed, while it was clear that the global average temperature was increasing. I use global warming if I want to emphasis the temperature change and climate change when I want to include all the other changes in the water cycle and circulation. These colleagues do the same and provide more history.

Climate models are not essential for basic understanding

Scott Adams assertion: 2. Prediction models are complicated. When things are complicated you have more room for error. Climate science models are complicated.

Yes, climate models are complicated. They synthesise a large part of our understanding of the climate system and thus play a large role in the synthesis of the IPCC. They are also the weakest part of climate science and thus a focus of the mitigation sceptical movement.

However, when it comes to the basics, climate model are not important. We know about the greenhouse effect for well over a century, long before we had any numerical climate models. That increasing the carbon dioxide concentration of the atmosphere leads to warming is clear, that this warming is amplified because warm air can contain more water, which is also a greenhouse effect is also clear without any complicated climate model. This is very simple physics.

The main role of climate models is trying to find reasons to expect the climate to respond differently from its response in the past or whether there are mechanisms beyond the simply physics that are important. The average climate sensitivity from climate models is about the same as for all the other lines of evidence. Furthermore, climate models add regional detail, especially when in comes to precipitation, evaporation and storm. These are helpful to better plan adaptation and estimate the impacts and costs, but are not central for the main claim that there is a problem.

Model tuning not important for basic understanding

Scott Adams assertion: 3. The models require human judgement to decide how variables should be treated. This allows humans to “tune” the output to a desired end. This is the case with climate science models.

Yes, models are tuned. Mostly to get the state of the atmosphere right, the global maps of clouds and precipitation, for example. In the light of my answer to point 2, this is not important for the question whether climate change is real.

The consensus is a result of the evidence

Scott Adams assertion: 4. There is a severe social or economic penalty for having the “wrong” opinion in the field. As I already said, I agree with the consensus of climate scientists because saying otherwise in public would be social and career suicide for me even as a cartoonist. Imagine how much worse the pressure would be if science was my career.

It is clearly not career suicide for a cartoonist. If you claim that you only accept the evidence because of social pressure, you are saying you do not really accept the evidence.

Scott Adams sounds as if he would like scientists to first freely pick a position and then only then look for evidence. In science it should go the other way around.

This seems to be the main argument and shows that Scott Adams knows more about office workers than about the scientific community. If science was your career and you would peddle the typical nonsense that comes from the mitigation sceptical movement that would be bad for your career. In science you have to back up your claims with evidence. Cherry picking and making rookie errors to get the result you would like to get are not helpful.

However, if you present credible evidence that something is different that is great, that is what you become scientist for. I have been very critical of the quality of climate data and our methods to remove data problems. Contrary to Adams' expectation this has helped my career. Thus I cannot complain how climatology treats real skeptics. On the contrary, a lot of people supported me.

I was highly critical of IPCC AR4 Chapter 6, so much so that the [mitigation skeptical] Heartland Institute repeatedly quotes me as evidence that the IPCC is flawed. Indeed, I have been unable to find any other review as critical as mine. I know "because they told me" that my reviews annoyed many of my colleagues, including some of my [RealClimate] colleagues, but I have felt no pressure or backlash whatsover from it. Indeed, one of the Chapter 6 lead authors said “Eric, your criticism was really harsh, but helpful "thank you!"

If you have the evidence there is nothing better than challenging the consensus. It is also the reason to become a scientist. As a scientist wrote on Slashdot:

Look, I'm a scientist. I know scientists. I know scientists at NOAA, NCAR, NIST, the Labs, in academia, in industry, at biotechs, at agri-science companies, at space exploration companies, and at oil and gas companies. I know conservative scientists, liberal scientists, agnostic scientists, religious scientists, and hedonistic scientists.

You know what motivates scientists? Science. And to a lesser extent, their ego. If someone doesn't love science, there's no way they can cut it as a scientist. There are no political or monetary rewards available to scientists in the same way they're available to lawyers and lobbyists.

Scientists consider and weigh all the evidence

Scott Adams assertion: 5. There are so many variables that can be measured – and so many that can be ignored – that you can produce any result you want by choosing what to measure and what to ignore. Our measurement sensors do not cover all locations on earth, from the upper atmosphere to the bottom of the ocean, so we have the option to use the measurements that fit our predictions while discounting the rest.

No, a scientist cannot produce any result they "want" and an average scientist would want to do good science not get a certain result. The scientific mainstream is based on all the evidence we have. The mitigation sceptical movement behaves in the way Scott Adams expects and likes to cherry pick and mistreat data to get the results they want.

Arguments from the other side only look credible

Scott Adams assertion: 6. The argument from the other side looks disturbingly credible.

I do not know which arguments Adams is talking about, but the typical nonsense on WUWT, Breitbart, Daily Mail % Co. is made to look credible on the surface. But put on your thinking cap and it crumbles. At least check the sources. That reveals most of the problems very quickly.

Most of these zombie myths are debunked on RealClimate or Skeptical Science. If it is a recent WUWT post and you do not mind some snark you can often find a rebuttal the next day on HotWhopper. Media articles are regularly reviewed by Climate Feedback, a group of climate scientists, including me. They can only review a small portion of the articles, but it should be enough to determine which of the "sides" is "credible". If you claim you are sceptical, do use these resources and look at all sides of the argument.

While political nonsense can be made to look credible, the truth is often complicated and sometimes difficult to convey. There is a big difference between qualified critique and uninformed nonsense. Valuing the strength of the evidence is part of the scientific culture. My critique of the quality of climate data is part of that. There are also real scientific problems in understanding changes of clouds, as well as the land and vegetation. These are important for how much the Earth will respond. Although the largest source of uncertainty is how much we will do to stop the problem.

There are real scientific problems when it comes to assessing the impacts of climate change. That often requires local or regional information, which is a lot more difficult than the global average. Many impacts will come from changes in severe weather, which are by definition rare and thus hard to study. For many impacts we need to know several changes at the same time. For droughts precipitation, temperature, humidity or the air and of the soil, the insolation are all important. Getting them all right is hard.

How humans and societies will respond to the challenges posed by climate change is an even more difficult problem and beyond the realm of natural science. Not only the benefits, but also the costs of reducing greenhouse gas emissions are hard to predict. That would require predicting future technological, economic and social development.

When it comes to how big climate change will be and its impacts I am sure we will see some surprises. What I do not understand is why some are arguing that this uncertainty is a reason to wait and see. The surprises will not only be nice, they will also be bad and all over increase the risks of climate change and make the case to speed up solving this solvable problem stronger.

Wednesday, 30 November 2016

In times of publish or perish, it can be tempting to put "hiatus" in your title and publish an average article on climate variability in one of the prestigious Nature journals. But my impression is that this does not explain all of the enthusiasm for short-term trends. Humans are greedy pattern detectors: it is better to see a tiger, a conspiracy or trend change one time too much, than one time too little. Thus maybe human have a tendency to see significant trends where statistics keeps a cooler head.

Whatever the case, I expect that also many scientists will be surprised to see how large the difference in uncertainty is between long-term and short-term trends. However, I will start with the basics, hoping that everyone can understand the problem.

Statistically significant

That something is statistically significant means that it is unlikely to happen due to chance alone. When we call a trend statistically significant, it means that it is unlikely that there was no trend, but that the trend you see is due to chance. Thus to study whether a trend is statistically significant, we need to study how large a trend can be when we draw random numbers.

For each of the four plots below, I drew ten random numbers and then computed the trend. This could be 10 years of the yearly average temperature in [[Yellowknife]]*. Random numbers do not have a trend, but as you can see, a realisation of 10 random numbers appears to have one. These trends may be non-zero, but they are not significant.

If you draw 10 numbers and compute their trends many times, you can see the range of trends that are possible below in the left panel. On average these trends are zero, but a single realisation can easily have a trend of 0.2. Even higher values are possible with a very small probability. The statistical uncertainty is typically expressed as a confidence interval that contains 95% of all points. Thus even when there is no trend, there is a 5% chance that the data has a trend that is wrongly seen as significant.**

If you draw 20 numbers, 20 years of data, the right panel shows that those trends are already quite a lot more accurate, there is much less scatter.

To have a look at the trend error for a range of different lengths of the series. The above procedure was repeated for lengths between 5 and 140 random numbers (or years) in steps of 5 years. The confidence interval of the trend for each of these lengths is plotted below. For short periods the uncertainty in the trend is enormous. It shoots up.

In fact, the confidence range for short periods shoots up so fast that it is hard to read the plot. Thus let's show the same data with different (double-logarithmic) axis. Then the relationship look like a line. That shows that size of the confidence interval is a power law function of the number of years.

The exponent is -1.5. As an example that means that the confidence interval of a ten year trend is 32 (101.5) times as large as the one of a hundred year trend.

Some people looking at the global mean temperature increase plotted below claim to see a hiatus between the years 1998 and 2013. A few years ago I could imagine people thinking: that looks funny, let's make a statistical test whether there is a change in the trend. But when the answer then clearly is "No, no way", and the evidence shows it is "mostly just short-term fluctuations from El Nino", I find it hard to understand why people believe in this idea so strongly that they defend it against this evidence.

Especially now it is so clear, without any need for statistics, that there never was anything like an "hiatus". But still some people claim there was one, but it stopped. I have no words. Really, I am not faking this dear colleagues. I am at a loss.

Maybe people look at the graph below and think, well that "hiatus" is ten percent of the data and intuit that the uncertainty of the trend is only 10 times as large, not realising that it is 32 times.

Maybe people use their intuition from computing averages; the uncertainty of a ten year average is only 3 times as large that of a 100 year average. That is a completely different game.

The plots below for the uncertainty in the average are made in the same way as the above for the trend uncertainty. Also here more data is better, but the function is much less steep. Plots of power laws always look the same, you need to compare the axis or the computed exponent, which in this case is only -0.5.

It is typical to use 30 year periods to study the climate. These so-called climate normals were introduced around 1900 in a time the climate was more or less stable and the climate needed to be described for agriculture, geography and the like. Sometimes it is argued that to compute climate trends you need at least 30 years of data, that is not a bad rule of thumb and would avoid a lot of nonsense, but the 30 year periods were not intended as a period on which to compute trends. Given how bad the intuition of people apparently is there seems to be no alternative to formally computing the confidence interval.

That short-term trends have such a large uncertainty also provides some insight into the importance of homogenisation. The typical time between two inhomogeneities is 15 to 20 years for temperature. The trend over the homogeneous subperiods between two inhomogeneities is thus very uncertain and not that important for the long-term trend. What counts is the trend of the averages of the homogeneous subperiods.

When this work began 25 years or more ago, not even our scientist colleagues were very interested. At the first seminar I presented about our attempts to identify the biases in Australian weather data, one colleague told me I was wasting my time. He reckoned that the raw weather data were sufficiently accurate for any possible use people might make of them.

Notes

* In Yellowknife the annual mean temperature is about zero degrees Celsius. Locally the standard deviation of annual temperatures is about 1°C. Thus I could conveniently use the normal distribution with zero mean and standard deviation one. The global mean temperature has a much smaller standard deviation of the fluctuations around the long-term trend.
** Rather than calling something statistically significant and thus only communicating whether the probability was below 5% or not, it fortunately becomes more common to simply give the probability (p-value). In the past this was hard to compute and people compared their computation to the 5% levels given in statistical tables in books. With modern numerical software there it is easy to compute the p-value itself.
*** Here is the cleaned R code to generated the plots of this post.

In the same story Dahr Jamail, a reporter who covers climate change, also recalls a quite dramatic nightmare: "It was simply a vision of a future Earth that was mostly barren of biological activity, one scarred by resource wars, and having seen a massive die off of humans, given we are already well into the sixth mass extinction event."

On Reddit a father wrote: "I have a 10 week old son and I'm terrified of his future. 4 years of actively ignoring climate change could mean never recovering. ... I'm just terrified." I prefer not to link to it, but someone even wrote to have suicidal thoughts because of climate change.

Climate change is a serious problem, but I see no need for such despair. We are on our way to solving the climate crisis. I do understand why people in America feel more despair being confronted daily with the most insane denial that climate change is a problem.

That is a classic nightmare. You are in a car sitting next to Lamar Inhofe behind the wheel. You see a cliff at the end of the road and try to warn Anthony Goddard that he should break. Instead Tim Delingpole speeds up because "gasoline is life", claims that cars are a product of the free market, that thus nothing can be wrong with them and Malcolm Nova turns the radio extra loud to make conversation impossible. You shout and shout, but the cliff gets closer and closer. You shout so loud that you lose your voice. The second part of the nightmare where you fall down an infinitely deep cliff is more relaxing.

Albeit it does move

My feeling is that many people are flipping out because they have the feeling nothing is done to combat the problem. Now already for over 3 decades. This is amplified by completely crazy people denying the most basic and solid facts as a way to avoid an adult conversation about solutions. If we would not act, the situation would become dire. Especially if we would react with the same denial, stupidity and anger to the problems created by climate change: New Orleans 2.0, climate refugees and conflicts over water. If that is your assessment of the situation, it is natural to be very worried.

I am more relaxed because I have the feeling we are acting. It helps that live in Germany were nearly all people are reasonable, including the conservatives. Even the people in my life who identify as climate "sceptics" are mostly reasonable. They just want so much climate change not to be happening and most are irrationally hopeful to one day find the "error", but they do not produce bullshit on an industrial scale like American blogs and think tanks.

Only the German racists deny there is a problem. It could always be even better, but Germany is part of the solution. That gives me a different perspective. I do not look at the continually increasing CO2 concentrations and temperatures, but at the enormous growth rates of renewable energy and the clear improvements in energy efficiency.

A lot is happening already. The last 3 years the emissions from industry and fossil fuels were stable, that used to happen only during world-wide recessions. That is a sign that renewable energy and energy efficiency policies and technology are starting to work. Most of the global new power generating capacity and investments are already carbon free. The next step is that also most new production is renewable, then we need to electrify the rest of the economy and use the market and technology to bring supply and demand together. It is still a long way, but I feel it is moving.

If anyone had a nightmare the last week, Donald Bannon likely had weird orange hair. Then it is important to realise that America is no longer that important. To quote myself:

The main question is whether America's refusal to act will reduce the willingness to act in the rest of the world. America by itself is no longer a major player and only emits 16% of all greenhouse gasses. Inaction in America is thus bad, but if limited to several years, and Trump is 70, a limited problem. The emissions should be zero in 2050. The danger is when this goes on for too long and when the rest of the world would be discouraged from acting or when international conflict makes global collaboration impossible.

European Union Climate Commissioner Miguel Arias Canete said: "The world is on the brink of an energy revolution." The rest of the world may well see it as a great business opportunity that the USA is missing out on the technologies that will shape the next century in this critical moment. Maybe Trump will even speed up the international energy transition.

The state of the climate

But, let's take a step back. Some people worry about 4°C of warming or more with the justified nightmare scenarios that come with it. 4°C for 2100 and more afterwards is what science expects in case of no action. The figure from the IPCC report's summary for policy makers show no action in red and a very optimistic action scenario in blue.

The big unknown is what countries will do beyond 2030. The Paris pledges do not go beyond 2030, but first countries have started defining their goals for 2050. The idea of Paris is that every 5 years the pledges become stronger if that is necessary. In that respect one should mainly look whether the next years are more or less on track.

Citizens of the world will have to demand of their governments to make these promises reality, but I feel it is fair to say that the worst worst-case scenarios are off the table. With Trump's election some of the best-case scenario's are unfortunately also less likely. I still have my personal best-case scenario where renewable energy becomes so inexpensive that the carbon bubble bursts and the Paris promises on energy are over-fulfilled without any further government action.

At the end of 2015, renewable capacity in place was enough to supply an estimated 23.7% of global electricity, with hydropower providing about 16.6%. Most important are likely solar and wind, they grow fastest and have the largest potential. At the moment they are at 1.4% of the world’s final energy consumption. That means that now the rest of the energy sector starts to notice their growth, which were the corporate resistance in the US comes from. Wind is growing by 14% every year and solar by 20%. 20% growth means doubling every 4 years, that is powerful growth. If we can keep that up that would mean: 1% (now), 2% (2020), 4% (2024), 8% (2028), 16% (2032), 32% (2036). It will likely gradually slow down, but it shows that it is possible to arrive at 100% soon, hopefully in 2050.

The group Climate Mobilization pledges to fight for 100% reduction in CO2 emission in the USA in 2025. That would be fast and thus more costly. Personally I would be happy to pay that price, already for the clean air and to see less species going extinct. This mobilization could be a response to the insane radicalization of the US anti-environmental movement.

Economist Jeffrey Sachs also expects that the U.S. will become a pariah state if Trump pulls out of Paris Climate Accord. That comes on top of the power loss from having an incompetent uninterested buffoon as president, a president that cannot give security guarantees because he likes to renegotiate deals, the damage to the US from cancelling the hard-fought global agreement on Iran's nuclear power program, and the transfer of power to China if the TPP is cancelled. Let's see if wrecking the climate is so dear to Trump that he is willing to pay that price. That is probably what Bill O'Reilly fears. That could mean less fresh and joyous wars and less dead Muslims. Let's see if Trump is willing to pay this price.

We had about 1°C of warming since 1900. Thus we are about halfway to the internationally agreed 2°C limit.

It will take time to transform the energy system, this is infrastructure that is build to work for decades, and the warming would continue for some time if we abruptly stopped emitting CO2. Because of the heat capacity of the oceans we are not at the equilibrium temperature yet that corresponds to the current CO2 concentrations; like it takes time until a water kettle boils because of the heat capacity of the water.

Combustion of fossil fuels produces tiny airborne particles (aerosols), which cool the temperature somewhat, once we stop with fossil fuels this would produce a little warming (~0.2°C).

If you take these delays into account, it will be work to stay below 2°C, but it is still possible to stay below it. One reason some people are freaking out is because some speak as if this 2°C level is a brick wall. This is not true. This limit is a political compromise. If changing the energy system were easy, we would have agreed on no more than 1°C or even less long time ago. It is a compromise between the costs of a fast transition and the costs of adaptation and the damages due to climate change.

I would personally have preferred a more ambitious compromise, but there is no brick wall or cliff at 2°C. Climate change will gradually become more risky. Similarly, it would reduce the risk if we could stay well below 2°C.

Climate change is a stressor. An important one because it stresses so many things that are important to us. Like climate change itself, these problems are solvable, we just need the political will to do so. What the impacts will thus be also depends on whether humanity gets its act together. If people like Trump are in power a Mad Max scenario is a much higher risk.

The US political system is a mess. We need to get money out of US politics. Trump will make this worse. He is already packing his cabinet with lobbyists. His tax plans and deregulation will further increase inequality, increase the power of the wealthy and give them more money to corrupt the political process. I like Wolf PAC, but there are many other groups working on this. Join the Democrat party (with some friends) and try to throw the corporatists out.

When it comes to climate change itself, join 350 to divest fossil fuel companies. With the renewable energy age so close and the remaining carbon budget not allowing for new fossil fuel infrastructure, the economic case against fossil fuel investments is stronger than ever. New infrastructure that would need to be profitable for decades, well after Trump is dead.

Hopefully the states, cities, private sector and citizens will pick up the pace to compensate for the counter-productive behaviour of the federal government. It is likely more productive to focus on solutions and not climate change itself. Denying climate change has become part of their identity for many Republicans. There are no arguments that could convince these people to change their public position. However, renewable energy is, for example, immensely popular with everyone, also with Republicans. There are even green tea parties against attempts of state governments to help their cronies in the utilities and make it more difficult to install solar on the roofs of homes.

If you have money, investing in renewable energy (in the USA) now will be more useful than ever. It would decrease the market for new fossil fuel infrastructure and support solar and wind companies over the Trump bump. I would be surprised if anyone would start to plan for a new coal power plant at this time. It takes a long time until it is running and would need to run a long time. Trump is 70 years old and will not be around forever and after that the investment will make losses. Maybe even before that because of cheap gas and renewables.

The energy sector is nowadays only 6% of the global economy; it is thus easier than one may think to move it. Once wind or solar is running, nothing can compete with their marginal costs. The best way would be to join or start an energy cooperative with your friends and family. That gets more people involved.

Climate change is solvable and I am confident we will. The real problem, the big problem is not climate change. It is us, as Prince EA beautifully explains below.

Thursday, 10 November 2016

It is a dreary dark rainy cold day in Bonn. The right setting for the catastrophe that just happened in America.

German children's radio tries to explain why the adults are freaking out. They said Trump main claim was to make America great again, which everyone can read into it what they like and is a sign for his lack of clear policies. And they told the kids he denies climate change and wants to build a wall.

That is the worst case scenario. The good case scenario would be George W. Bush on steroids. More inequality; Trump plans gigantic tax cuts for his billionaire buddies; the corrupt Republican Congress wants the same. Utter incompetence and less regulation for the banks will produce private gains (bank shares are 4 to 5% up) that will likely lead to another 2008-style economic recession that socializes the losses. Gratuitous deadly wars that benefit the military industry; Trump wants to increase the defense budget, surrounds himself with war hawks and likes aggressive posturing. And a federal government in the pockets of coal and oil that will try to emit more CO2 to green the planet.

Many people seem to have been surprised by Trump winning. The Huffington Post was very sure Clinton would win and attacked Nate Silver with the flimsiest of arguments and mistakes for hyping the uncertainty: What's wrong with 538?What's wrong with HuffPo when a pseudo-German knows US polling better? Also after the election Silver is still sometimes seen to have been wrong because he gave Trump 30% chance. 30% does not mean he will loose. It means that every 3 elections a catastrophe will happen.

I sometimes wonder if people make the same mistake for climate change. If the chance that they are directly affected is less than 50%, then it does not exist. It is a wonder people take an umbrella with them when the chance of rain is 30% and have a fire insurance. Maybe that is because we have more experience with rain and a longer tradition of cities burned to the ground. Even if it not certain, a chance of a huge catastrophe is a strong reason to act.

Please see the Trump presidency in the same way. By all means hope for the best case scenario, but be prepared for the worst case scenario. Do not keep an open mind about Trump, be vigilant, start organizing and informing yourself now. Read up on German and Italian history. Inform yourself what is happening in Russia and The Philippines. Bob Altemeyer's The Authoritarians is great book for insight into their behavior and thinking.

Make sure everyone knows about the [[Reichstag fire]] and how it was used to destroy the German democracy. A more recent US example is 9/11 and how it was used to take many constitutional freedoms away. This expansion of government power will now allow Trump to spy, jail and intimidate the opposition. People need to know this, so they can recognize the pattern and protest before it is too late.

Most of this post is aimed at progressives, I presume they read my blog most. If you are a rational conservative, like most conservatives in continental Europe, please speak up, please inform and talk to your peers. They will listen to you most. "America first" only means that the others have it worse, not that America has it good. Fascists are not conservatives, they are revolutionaries.

Germany and America are connected by values of democracy, freedom, and respect for the law and the dignity of man, independent of origin, skin colour, religion, gender, sexual orientation, or political views. I offer the next President of the United States close cooperation on the basis of these values.

The video below given an overview of the worst transgressions of Trump. The real transgressions, not the naughty words US TV concentrated on.

Climate change

Trump is not clear on most policies, but quite clear in trying to make climate change as worse as possible. Reversing any policies made under the black president, stimulating coal, no regulations on fracking and he wants to get out of the Paris climate treaty. That is actually not possible, but he can simply not do what the USA promised. Shares of Peabody Energy, world's largest coal company, almost doubled in two days after the election; okay, they were not worth much to begin with. On the positive side, Trump did hint at supporting renewable energy for reasons other than climate change.

This would make Trump the only head of state in the world that rejects climate change. By going rogue on climate America will isolate itself. China warned twice ahead of the election that Trump was not a good idea; that is unprecedented. Europe will not view this any kinder. I see the same happening in the field of international security. A president who prides himself on re-negotiating deals and ripping off his partners cannot give security guarantees. This will strengthen regional powers. Trump's presidency may well be the end of American hegemony. Hopefully the transition to a multi-polar world will be peaceful.

When it comes to climate change again a range of scenarios is possible. The main question is whether America's refusal to act will reduce the willingness to act in the rest of the world. America by itself is no longer a major player and only emits 16% of all greenhouse gasses. Inaction in America is thus bad, but if limited to several years, and Trump is 70, a limited problem. The emissions should be zero in 2050. The danger is when this goes on for too long and when the rest of the world would be discouraged from acting or when international conflict makes global collaboration impossible.

To fight climate change, the main problem in this phase is the energy transition. Here I am quite hopeful because I think we won this battle before this election, maybe even in the USA. Prices of renewable energy are dropping fast. That is partially technological advances and larger markets and partially historical low interest rates. Trump's incompetence and danger to the global economy will keep interest rates low for years to come. In large parts of the world renewable energy is already competitive without any government help, with prices dropping this region will become increasingly larger. Many of the richer US states are run by Democrats and they will continue setting efficiency standards and stimulating the energy transition, which is very popular in the population.

I could be wrong. Not too long ago I still expected that a price on CO2 emissions to compensate for the damages would be necessary to make renewable power competitive. It would still speed the transition up and the transition should go faster, but I feel it is unstoppable due to economic forces.

The Trump presidency has a nice plus for the German car industry. It was somewhat slow with electric cars, but now has a good chance to dominate this industry of the 21st century. Same for wind power and machines to produce solar panels.

The future

How bad it will be be, will depend on us.

The US media is a mess. Especially television. It is no wonder that Trump would have lost bigly had only young people voted; they are not indoctrinated by emotional one-sided sensationalist television programs. Getting rid of my TV was the best decision in my life.

This is how the future voted. This is what people 18-25 said in casting their votes. We must keep this flame alight and nurture this vision. pic.twitter.com/ivuXrar869

It is important to build up alternative independent media. I would expect to get the highest quality from media sponsored by members, which means they do not depend on clicks, which stimulates sensationalism, and they do not depend on billionaires, which biases the reporting. Examples on YouTube for general news are TYT (partially member funded) and Secular Talk. If your (local) newspaper is decent, subscribe. Become member of The Guardian. Newspapers do a lot of the reporting. TV just rehashes their work superficially.

The US political system is a mess. We need to get money out of US politics. Trump will make this worse. His tax plans and deregulation will increase inequality, increase the power of the wealthy and give them more money to corrupt the political process. I like Wolf PAC, but there are many other groups working on this. Join the Democrat party and try to throw the corporatists out. Campaign for Sanders to clean the stable as new head of the DNC.

When it comes to climate change, join 350 to divest fossil fuel companies. With the renewable energy age so close and the remaining carbon budget not allowing for new fossil fuel infrastructure, the economic case against fossil fuel investments is strong. Infrastructure that would need to be profitable for decades, well after Trump is dead. Banking is global; everyone can help. Also divest personally, join an [[ethical bank]]; their rates are competitive.

If you have money, investing in renewable energy (in the USA) now will be more useful than ever. It would decrease the market for new fossil fuel infrastructure and support these companies over the Trump bump. The energy sector is nowadays only 6% of the global economy; it is easier than one may think to move it. Once wind or solar is running, nothing can compete with the marginal costs of renewable energy. The best way would be to join or start an [[energy cooperative]] with you friends and family. That gets more people involved.

Many more things will have to change, such as the local infrastructure and there are many more environmental problems. Friends of the Earth International is a bottom up democratic environmental group. A good place to find like minded people.

The situation for climate science will probably get hostile. Trump has vowed to defund it. His friends do their best to harass scientists. It will be hard to distinguish between meteorology and climatology for most of the research and I hope the states will be able to compensate for some of the funding. European countries may be interested in top American researchers at a bargain. Still the Climate Science Legal Defense Fund will be more important than ever.

More than about climate change, I worry about human rights, freedom and peace. America elected a bigot. Lets make sure the bigots do not conquer the public space. Only 1/2 of electorate voted. Only 1/2 voted Trump. Only 1/2 selected him in the primaries. Even of those people not all selected him because he is a bigot. After the Brexit there was a rise in violence against minorities. It is bad that so many did not mind a bigot much, but remember that the bigots willing to use violence are just a few percent of the population. We are the majority.

Planned Parenthood and the ACLU are more important than ever. Even if you do not want to join any organizations, please use them to information to know what is going on before it is too late.

Friday, 4 November 2016

The US media is a catastrophic failure and is about to create a catastrophe this Tuesday. The focus is on personalities, mud slinging and conflict, which attract attention and are safe he-said she-said topics for the media. While there is nearly no attention for policy, which makes it harder to avoid taking a position. Sometimes single policies are contrasted with each other, but overviews are dearly missing.

As a consequence there is now a real possibility Trump could become president. Most polling aggregators see the chance of Trump winning as a few to a dozen percent.

Sam Wang at Princeton Election Consortium has Clinton with a better than 97% chance to win, Drew Linzer at Daily Kos has her with 92%, and NYT Upshot has her at 86% currently to win?

Polls do a lot of bias correction, certain groups are polled less well, for example young people. It is very hard to guess who will actually show up for the election. The people who pick up the phone may be different from the ones that do not. People may vote differently from what they say; to keep the peace in the family or because they see their preference as socially unacceptable. People who say they vote for another party than the last election often do not do so. The polls were collectively wrong for the Brexit referendum in the UK, which is similar to the Trump campaign, many bigots voting, many protest voters that do not expect their vote to count.

The increasing chance of a Trump presidency this week made the Dollar drop 1%, the NASDAQ 4$ and the S&P 500 2.6%. If you believe the chance of Trump winning is less than a fourth, there is money lying on the floor of the betting market. Do pick it up.

Climate

I just came by someone who wants to vote Jill Stein (Green party) because Clinton and Trump are both bad and Clinton has supported fracking as Secretary of State. I understand that Stein has to say they are equally bad not to look like a spoiler and that she attacks Clinton more because that is where most of her votes will come from. I would not be able to live with myself having to do that, but that is her unfortunate role in this election. That is what she was elected to do by the members and she accepted this role when she did not know yet that this would turn out this horribly.

But if you care for the environment, there is no way you can risk Trump getting elected. Trump would certainly not stop fracking. He would allow fracking without any regulation: He wants to close the Environmental Protection Agency (EPA) and wants to kill 80% of regulations. Whatever that means.

An analysis from Lux Research suggests that Trump’s policies would leave CO2 emissions 16% higher after 8 years than Clinton’s. That is a large difference on the way to zero in 2050 and will also have its influence afterwards and on the willingness of other countries to act.

Do we have 4 years to lose on climate change? If it is just four years; either because the entire world is on fire and international negotiations no longer work, or because the next election is cancelled.

Money in politics

Clinton was a terrible pick for the Democrats. In the time people are completely fed up with the establishment and the corruption in US politics, the DNC in their infinite wisdom selected the symbol of the establishment as their candidate. During the primaries I made the case for Bernie Sanders, he would have won this election in a land slide. But reality is what it is. There this election is similar to the climate "debate" where Americans have trouble accepting the world as it is.

Unfortunately Clinton's competence and hard work can also be seen in how much money she raised and her donors are mostly not giving her money for a better world. For the companies it is an investment, they are not charities. Still Clinton wants to reverse Citizens-United, while Trump talks about corruption, but is a major corrupter himself and has no plans to stop it. Naturally he will not stop the corruption, he benefits from the system as a billionaire, that is how he stays a billionaire. His entire life has been about getting rich by conning people into thinking he has something to offer.

Trump presents himself as the anti-establishment choice, but is just as much part of it as Clinton. They went to the same parties and hung out with the same people. Trump plans to massively lower the taxes for himself and this posh peers, which will create an enormous deficit, while Clinton will raise taxes on the rich to reduce them for the middle class. A politician does not have to do everything rich donors want, also they only have two options.

This in not a normal election

Trump is a terrible human being. He wants to discriminate against every group possible. He started his campaign calling most Mexicans rapists. Projection. He wants to ban Muslims from coming into the USA, which is immoral and against the Freedom of Religion in the US constitution. The Jewish Anti-defamation league immediately protested against tbis because they understand were this leads to. Next Trump told an audience of Jewish people that they all like re-negotiating deals and put the star of David next to Clinton. There is a reason nearly no African American supports Trump. There is a reason David Duke and the KKK support Trump; they see the difference.

Trump is a terrible human being. Not for using the word "pussy", but because he "would not even wait" (for concent), as he said himself and as afterwards more than a dozen victims confirmed. His ex-wife testified in court that Trump had raped her. After the election, Trump will have to go to court for allegedly raping a 13 year old girl at one of the teen sex party of his billionaire buddy Epstein.

Trump is a terrible human being. He wants to bring back torture worse than waterboarding. Even if torture does not help, just for the sadistic pleasure of hurting a subordinate. At least he apparently knows that torture does not work, it only produces fake confessions. He wants to kill the families of suspected terrorists. The Nazis called this punishing of innocent relatives "Sippenhaft". Deeply disturbing. He admires the dictators of North Korea, The Philippines and Russia and their violent actions.

The middle class in America did not get a raise in a long time. The upper class did. A lot. The main reason is corruption. Middle class incomes rose with productivity until the Supreme Court ruled that money is speech and corporations have human rights. Trump would nominate judges like Anthony Scalia and there are many judges up for reappointment. A Trump presidency would solidify corporate power for decades to come.

The middle class will not benefit when Trump starts trade wars. He has threatened to default on the US debt. If he repeats that statement, even without doing so, that will produce an instant world recession. His enormous tax cuts for the super rich and the huge deficit that makes are both really bad for the economy.

The middle class will not benefit when Trump starts wars. He wants increase the military budget even further, although it is already 34 percent of the world total and more than the next 7 or 8 countries combined, many of which are currently allies. As an insecure uninformed and thin-skinned person who fears the Other it would only be a matter of time until he starts major wars. Clinton is hawkish, but also competent and diplomatic, which avoids wars. I would be surprised if she would kill more people than Trump and she would at least start her wars intentionally.

If America elects Trump, it will not be long until The Philippines and Russia are its only friends. And maybe North Korea. Economically Europe is a big as the USA. That the US is the main military power is our choice. That can change and a common threat will consolidate Europe. A lazy incompetent US president will not stop that.

If America lets a thin-skinned madman near the nuclear codes, Europe will build up its own nuclear arsenal to ensure Mutual Assured Destruction and a nuclear shield. In such a conflicted international situation, it would be hard to prevent Iran and other countries from obtaining nuclear weapons as well.

If America goes rogue on climate, I would expect the rest of the world to start Geo-engineering. If that hurts drought-prone US agriculture, that is a pity, but you had a choice in 2016 on the 8th of November.

Progressives and greens

Progressives and greens do not have much to win this presidential election (but a lot to lose). If you are considering voting for Jill Stein, why not instead become member of the Green party instead? Build up an organization at the local level, win local election, showcase successful politicians that can take the next step, so that in future elections the Greens have a real chance rather than only dividing the vote.

Some people make the argument that getting 5% of votes for the Green party would result in federal funding for the next election. The Green party is currently at less than 1.6% at Nate Silver's 538 and at 2.1% in the RealClearPolitics average. Single cherry picked polls can naturally be higher. The results for a small party are very noisy, especially for the Green party with many young voters who are typically underrepresented in surveys. As a consequence polling organisations put a higher weight on the few young people they do get. Thus you have to average over many polls to get a reliable average. The green party will not more than double in 4 days.

Even if they do, for getting 5%, the Greens would receive about 10 million dollar in funding for the next election. In the last election there were 120 million votes, 5% of that is 6 million votes. If the Greens pass the threshold a vote would thus be worth about 2$. A donation to the Green party sounds like a better idea in Trumpy times. A donation of 1$ would be a very good deal for the Green party.

There are some progressives that argue that a president Trump will destroy the Republican party. That is utter nonsense. The Republicans are authoritarians, they will fall in line, you see it happening during the general election. If Trump becomes president there will be a lot of jobs available. That works wonders in stabilizing parties. In Europe we have more parties and they thus more often fail; they do so after losing, not after winning.

Positive change does not happen due to politicians. Real positive change is the result of activism, not of elections. Politicians implement the changes that they were forced to make. Even if well intended they only have to power to do good if they are forced to.

Do fight Clinton from the day of the election on. She will be much more responsive to pressure from greens and progressives than Trump would be. She is a good listener and she is competent. Things you cannot say about Trump. Do primary her in four years if she does not change considerably.

Especially fight to get money out of politics, there are many initiativesto do so. The problem is not individual politicians, the system is corrupt and corrupting. The systems needs to change, toppling persons in the system does not change it.

This is not fun anymore. If you think Trump will not do the atrocious things he promises. Think again. No one thought in Germany in 1930 that Hitler would do the things he promised in great detail in his book Mein Kampf. It did not start with the Holocaust, it started with large rallies, it ended with the Holocaust*. In the last more-or-less free election Hitler got a third of the votes and the conservatives and Christians helped him to power.

Who would stop a president Trump? The Republicans? The police? The NSA? The military?

With all the reservations about the donations to Clinton and her hawkishness, there is also a lot to like about her as a progressive, not only when it comes to the environment, but also when in comes to reducing inequality, schools, collage tuition and social issues. Obama can explain it best.

Related reading

A tale of two ethics. The ethic of conviction (Gesinnungsethik) and ethic of responsibility (Verantwortungsethik). Why many Germans think impractical idealism is immoral and why people holding opposite ethics may have a hard time talking with each other.

Monday, 10 October 2016

Historical climate data contains inhomogeneities, for example due to changes in the instrumentation or the surrounding. Removing these inhomogeneities to get more accurate estimates of how much the Earth has actually warmed is a really interesting problem. I love the statistical homogenization algorithms we use for this; I am a sucker for beautiful algorithms. As an observationalist it is great to see the historical instruments, read how scientists understood their measurements better and designed new instruments to avoid errors.

Still for science it would be better if future climatologists had an easier task and could work with more accurate data. Let's design a climate-change-quality network that is a stable as we can humanly get it to study the ongoing changes in the climate.

Especially now that the climate is changing, it is important to accurately predict the climate for the coming season, year, decade and beyond at a regional and local scale. That is information (local) governments, agriculture and industry needs to plan, adapt, prepare and limit the societal damage of climate change.

We are performing a unique experiment with the climate system and the experiment is far from over. It would also be scientifically unpardonable not to measure this ongoing change as well as we can. If your measurements are more accurate, you can see new things. Methodological improvements that lead to smaller uncertainties is one of the main factors that brings science forward.

A first step towards building a global climate reference network is agreeing on a concept. This modest proposal for preventing inhomogeneities due to poor observations from being a burden to future climatologists is hopefully a starting point for this discussion. Many other scientists are thinking about this. More formally there are the Rapporteurs on Climate Observational Issues of the Commission for Climatology (CCl) of the World Meteorological Organization (WMO). One of their aims is to:

Advance specifications for Climate Reference Networks; produce a statement of guidance for creating climate observing networks or climate reference stations with aspects such as types of instruments, metadata, and siting;

Essential Climate Variables

A few weeks ago Han Dolman and colleagues wrote a call to action in Nature Goescience titled "A post-Paris look at climate observations". They argue that while the political limits are defined for temperature, we need climate quality observations for all essential climate variables listed in the table below.

We need continuous and systematic climate observations of a well-thought-out set of indicators to monitor the targets of the Paris Agreement, and the data must be made available to all interested users.

I agree that we should measure much more than just temperature. It is quite a list, but we need that to understand the changes in the climate system and to monitor the changes in the atmosphere, oceans, soil and biology we will need to adapt to. Not in this list, but important are biological changes, especially ecology needs support for long-term observational programs, because they lack the institutional support the national weather services provide on the physical side.

Measuring multiple variables also helps in understanding measurement uncertainties. For instance, in case of temperature measurements, additional observations of insolation, wind speed, precipitation, soil temperature and albedo are helpful. The US Climate Reference Network measures this wind speed at the height of the instrument (and humans) rather than at the meteorologically typical height of 10 meter.

Because of my work, I am mainly thinking of the land surface stations, but we need a network for many more observations. Please let me know where the ideas do not fit to the other climate variables.

Comparable networks

There are comparable networks and initiatives, which likely shape how people think about a global climate reference network. Let me thus describe how they fit into the concept and where they are different.

There is the Global Climate Observing System (GCOS), which is mainly an undertaking of the World Meteorological Organization (WMO) and the Intergovernmental Oceanographic Commission (IOC). They observe the entire climate system; the idea of the above list of essential climate variables comes from them (Bojinski and colleagues, 2014). GOCS and its member organization are important for the coordination of the observations, for setting standard so that measurements can be compared and for defending the most important observational capabilities against government budget cuts.

Especially important from a climatological perspective is a new program to ask governments to recognize centennial stations as part of the world heritage. If such long series are stopped or the station is forced to move, a unique source of information is destroyed or damaged forever. That is comparable to destroying ancient monuments.

A subset of the meteorological stations are designated as GCOS Surface Network measuring temperature and precipitation. These stations have been selected for their length, quality and to cover all regions of the Earth. Its monthly data is automatically transferred to global databases.

National weather services normally take good care of their GCOS stations, but a global reference network would have much higher standards and also provide data at better temporal resolutions than monthly averages to be able to to study changes in extreme weather and weather variability.

There is already a global radiosonde reference network, the GCOS Reference Upper-Air Network (GRUAN, Immler and colleagues, 2010). This network provides measurements with well characterized uncertainties and they make extensive parallel measurements when they transition from one radiosonde design to the next. No proprietary software is used to make sure it is know exactly what happened to the data.

Currently they have about 10 sites, a similar number is on the list to be certified and the plan is not make this a network of about 30 to 40 stations; see map below. Especially welcome would be partners to start a site in South America.

The observational system for the ocean Argos is, as far as I can see, similar to GRUAN. It measures temperature and salinity (Roemmich and colleagues, 2009). If your floats meet the specifications of Argos, you can participate. Compared to land stations the measurement environment is wonderfully uniform. The instruments typically work a few years. Their life span is thus between a weather station and a one-way radiosonde ascent. This means that the instruments may deteriorate somewhat during their lifetimes, but maintenance problems are more important for weather stations.

Finally there are a number of climate reference networks of land climate stations. The best known is probably the US Climate Reference Network (USCRN, Diamond and colleagues, 2013). It has has 131 stations. Every station has 3 identical high quality instrument, so that measurement problems can be detected and the outlier attributed to a specific instrument. To find these problems quickly all data is relayed online and checked at their main office. Regular inspections are performed and everything is well documented.

The USCRN has selected new locations for its stations, which are expected to be free of human changes of the surroundings in the coming decades. This way it takes some time until the data becomes climatologically interesting, but they can already be compared with the normal network and this gives some confidence that its homogenized data is okay for the national mean; see below. The number of stations was sufficient to compute a national average in 2005/2006.

Other countries, such as Germany and the United Kingdom, have opted to make existing stations into a national climate reference network. The UK Reference Climatological Stations (RCS) have a long observational record spanning at least 30 years and their distribution aims to be representative of the major climatological areas, while the locations are unaffected by environmental changes such as urbanisation.

German Climate Reference Station which was founded in 1781 in Bavaria on the mountain Hohenpeißenberg. The kind of weather station photo, WUWT does not dare to show.

In Germany the climate reference network are existing stations with a very long history. Originally they were the stations where conventional manual observations continued. Unfortunately, they will now also switch to automatic observations. Fortunately, after making a long parallel measurement to see what this does to the climate record*.

An Indian scientist proposes an Indian Climate Reference Network of about 110 stations (Jain, 2015). His focus is on precipitation observations. While temperature is a good way to keep track on the changes, most of the impacts are likely due to changes in the water cycle and storms. Precipitation measurements have large errors; it is very hard to make precipitation measurements with an error below 5%. When these errors change, that produces important inhomogeneities. Such jumps in precipitation data are hard to remove with relative statistical homogenization because the correlations between stations are low. If there is one meteorological parameters for which we need a reference network, it is precipitation.

Network of networks

For a surface station Global Climate Reference Network, the current US Climate Reference Network is a good template when it comes to the quality of the instrumentation, management and documentation.

A Global Climate Reference Network does not have to do the heavy lifting all alone. I would see it as the temporally stable backbone of the much larger climate observing system. We still have all the other observations that help to make sampling errors smaller and provide the regional information you need to study how energy and mass moves through the climate system (natural variability).

We should combine them in a smart way to benefit from the strengths of all networks.

The Global Climate Reference Network does not have to be large. If the aim is to compute a global mean temperature signal, we would need just as many samples as we would need to compute the US mean temperature signal. This is in the order of 100 stations. Thus on average, every country in the world would have one climate reference station.

The figure on the right from Jones (1994) compares the temperature signal from 172 selected stations &mdsh; 109 in the Northern Hemisphere. 63 in the Southern Hemisphere. &mdash with the temperature signal computed from all available stations. There is nearly no difference, especially with respect to the long term trend.

Callendar (1961) used 80 only stations, but his temperature reconstruction fits quite well to the modern reconstructions (Hawkins and Jones, 2013).

Beyond the global means

The number of samples/stations can be modest, but it is important that all climate regions of the world are sampled; some regions warm/change faster than others. It probably makes sense to have more stations in especially vulnerable regions, such as mountains, Greenland, Antarctica. We really need a stable network of buoys in the Arctic, where changes are fast and these changes also influence the weather in the mid-latitudes.

Crew members and scientists from the US Coast Guard icebreaker Healy haul a buoy across the sea ice during a deployment. In the lead an ice bear watcher and a rescue swimmer.

To study changes in precipitation we probably need more stations. Rare events contribute a lot to the mean precipitation rate. The threshold to get into the news seems to be the rain sum of a month falling in on one day. Enormous downpours below that level are not even newsworthy. This makes the precipitation data noisy.

To study changes in extreme events we need more samples and might need more stations as well. How much more depends on how strong the synergy between the reference network and the other networks is and thus how much the other networks could then be used to produce more samples. That question needs some computational work.

The idea to use 3 redundant instruments in the USCRN is something we should also use in the GCRN and I would propose to also to create clusters of 3 stations. That would make it possible to detect and correct inhomogeneities by making comparisons. Even in a reference network there may still be inhomogeneities due to changes in the surrounding or management (which were not noticed).

We should also carefully study whether is might be a problem to only use pristine locations. That could mean that the network is no longer representative for the entire world. We should probably include stations in agricultural regions, that is a large part of the surface and they may respond differently from natural regions. But agricultural practices (irrigation, plant types) will change.

Starting a new network at pristine locations has as disadvantage that it takes time until the network becomes valuable for climate change research. Thus I understand why Germany and the UK have opted to use locations where there are already long historical observations. Because we only need 100+ stations it may be possible to select existing locations from the 30 thousand stations we have that are and likely stay pristine in the coming century. If not, I would not compromise and use a new pristine location for the reference network.

Finally, when it comes to the number of stations, we probably have to take into account that no matter how much we try some stations will become unsuitable due to war, land-use change and many other unforeseen problems. Just look back a century and consider all the changes we experienced, the network should be robust against such changes for the next century.

Absolute values or changes

Argos (ocean) and GRUAN (upper air) do not specify the instruments, but set specification for the measurement uncertainties and their characterization. Instruments may thus change and this change has to be managed. In case of GRUAN they perform many launches with multiple instruments.

For a climate reference land station I would prefer to keep the instruments exactly the same design for the coming century.

To study changes in the climate climatologists look at the local changes (compute anomalies) and average those. We had a temperature increase of about 1°C since 1900 and are confident it is warming. This while the uncertainty in the average absolute temperature is of the same order of magnitude. Determining changes directly is easier than first estimating the absolute level and then look whether it is changing. By keeping the instruments the same, you can study changes more easily.

This is an extreme example, but how much thermometer screens weather and yellow before they are replaced depends on the material (and the climate). Even if we have better materials in the future, we'd better keep it the same for stable measurements.

For GRUAN managing the change can solve most problems. Upper air measurements are hard; the sun is strong, the air is thin (bad ventilation) and the clouds and rain make the instruments wet. Because the instruments are only used once, they cannot be too expensive. On the other hand, each time starting with a freshly calibrated instrument makes the characterization of the uncertainties easier. Parallel measurements to manage changes are likely more reliable up in the air than at the surface where two instruments measuring side by side can legitimately measure a somewhat different climate, especially when it comes to precipitation, where undercatchment strongly depends on the local wind or for temperature when cold air flows at night hugging the orography.

Furthermore, land observations are used to study changes in extreme weather, not just the mean state of the atmosphere. The uncertainty of the rain rate depends on the rain rate itself. Strongly. Even in the laboratory and likely more outside where also the influence factors (wind, precipitation type) depend on the rain rate. I see no way to keep undercatchment the same without at least specifying the outside geometry of the gauge and wind shield in minute detail.

The situation for temperature may be less difficult with high-quality instruments, but is similar. When it comes to extremes also the response time (better: response function) of the instruments becomes important and how much out-time the instrument experiences, which is often related to severe weather. It will be difficult to design new instruments that have the same response functions and the same errors over the full range of values. It will also be difficult to characterize the uncertainties over the full range of values and velocity of changes.

Furthermore, the instruments of a land station are used for a long time while not being observed. Thus weather, flora, fauna and humans become error sources. Instruments which have the same specifications in the laboratory may thus still perform differently in the field. Rain gauges may be more or less prone to getting clogged by snow or insects, more or less attractive for drunks to pee in. Temperature screens may be more or less prone to be blocked by icing or for bees to build their nest in. Weather stations may be more or less attractive to curious polar bears.

This is not a black and white situation. It will depend on the quality of the instruments which route to prefer. In the extreme case of an error free measurement, there is no problem with replacing it with another error free instrument. Metrologists in the UK are building an instrument that acoustically measures the temperature of the air, without needing a thermometer, which should have the temperature of the air, but in practice never has. If after 2 or 3 generations of new instruments, they are really a lot better in 50 years and we would exchange them, that would still be a huge improvement of the current situation with an inhomogeneity every 15 to 20 years.

The software of GRUAN is all open source. So that when we understand the errors better in future, we know exactly what we did and can improve the estimates. In case we specify the instruments, that would mean that we need Open Hardware as well. The designs would need to be open and specified in detail. Simple materials should be used to be sure we can still obtain them in 2100. An instruments measuring humidity using the dewpoint of a mirror will be easier to build in 2100 than one using a special polymer film. These instruments can still be build by the usual companies.

If we keep the instrumentation of the reference network the same, the normal climate network, the GCOS network will likely have better equipment in 2100. We will discover many ways to make more accurate observations, to cut costs and make the management more easy. There is no way to stop progress for the entire network, which in 2100 may well have over 100 thousand stations. But I hope we can stop progress for a very small climate reference network of just 100 to 200 stations. We should not see the reference network as the top of hierarchy, but as the stable backbone that complements the other observations.

Organization

How do we make this happen? First the scientific community should agree on a concept and show how much the reference network would improve our understanding of the climatic changes in the 21st century. Hopefully this post is a step in this direction and there is an article in the works. Please add your thoughts in the comments.

With on average one reference station per country, it would be very inefficient if every country would manage its own station. Keeping the high metrological and documentation standards is an enormous task. Given that the network would be the same size as USCRN, the GCRN could in principle be managed by one global organization, like USCRN is managed by NOAA. It would, however, probably be more practical to have regional organizations for better communication with the national weather services and to reduce travel costs for maintenance and inspections.

Funding

The funding of a reference network should be additional funding. Otherwise it will be a long hard struggle in every country involved to build a reference station. In developing countries the maintenance of one reference station may well exceed the budget of their current network. We already see that some meteorologists fear that the millennial stations program will hurt the rest of the observational network. Without additional funding, there will likely be quite some opposition and friction.

In the Paris climate treaty, the countries of the world have already pledged to support climate science to reduce costs and damages. We need to know how close we are to the 2°C limit as feedback to the political process and we need information on all other changes as well to assess the damages from climate change. Compared to the economic consequences of these decisions the costs of a climate reference network is peanuts.

The World Meteorological Organization had its congress last year. The directors of the national weather services have shown that they are not able to agree on the international sharing of data. For weather services selling data is often a large part of their budget. Thus the decision to share data internationally should be made by politicians who have the discretion to compensate these losses. In the light of the historical responsibility of the rich countries, I feel a global fund to support the meteorological networks in poor countries would be just. This would compensate them for the losses in data sales and would allow them to better protect themselves against severe weather and climate conditions.

Let's make sure that future climatologists can study the climate in much more detail.